High-Performance CO<sub>2</sub> Sequestration Solid Materials Consist of β-C<sub>2</sub>S and γ-C<sub>2</sub>S Binary Clinkers Synthesized from Carbide Slag and Sandstone: Sintering, Carbonation, and Microstructure
Xingang Wang, Hongyun Luo, Fubing Zou, Jiukai Cai, Yong Yu, Jian Fu
Abstract
In this work, we propose low-energy consumption and high-performance CO 2 sequestration solid materials consisting of β-C 2 S (dicalcium silicate) and γ-C 2 S binary clinkers synthesized by using carbide slag, sandstone, and ferroferric oxide (Fe 3 O 4 ). The performance controlling factors for carbonated compacts were investigated and found that the C 2 S clinker composition was the key factor. The presence of a small (i.e., 5.2%) amount of β-C 2 S in the mixture could reduce the first-stage activation energy during the carbonation reaction compared to that of powder (i.e., basically γ-C 2 S), thus accelerating the whole carbonation reaction. The compressive strength of carbonated compacts made from the mixture was nearly 2.5 times that of carbonated compacts made from powder (i.e., 116.8 and 47.4 MPa, respectively) after 24 h of CO 2 curing. The 24 h degree of carbonation of carbonated compacts made from the mixture was nearly 1.5 times that of carbonated compacts made from powder (i.e., 45.0 and 30.2%, respectively). This finding could provide guidance on the high-performance CO 2 sequestration solid materials from the view of adjustment of the proportion of β-C 2 S and γ-C 2 S in C 2 S binary clinkers by a one-step sintering reaction.